Slide fastener



Feb. 10,1970 A] FROHLICH 3,494,008

SLIDE FASTENER Filed July 14. 1967 2 Sheets-Sheet 1 7 4, x P 11 M Li 3e J FIGI FIG. 3

INVENIOR. AL FMS FROHL IC'H Arrows/5y FIGS Feb. 10, 1970 A. FROHLICH SLIDE FASTENER Filed July 14. 1967 2 Sheets-Sheet 2 INVENTOR. AU'WIVS FROHL/Ch (K r Rm;

4 TTORNEY United States Patent Int. Cl. A44b 19/02 US. Cl. 24-205.1 7 Claims ABSTRACT OF THE DISCLOSURE A slide-fastener stringer having a fabric tape formed With spaced-apart openings receiving the heads of a meandering or helicoidal continuous coupling element provided with retaining strands outwardly of the openings for preventing withdrawal of the heads therefrom.

This application is a continuation-in-part of my copending applications Ser. No. 624,647, Ser. No. 619,833 and Ser. No. 619,678, all filed Mar. 1, 1967.

My present invention relates to slide-fastener assem blies and, more particularly, to slide fastener arrangements in which a coupling element is received within a sleevelike formation of a woven support tape.

In my copending application Ser. No. 619,833, I have disclosed a slide-fastener assembly which makes it possible to secure the coupling elements thereof to the support tape of a slide-fastener stringer in an accurate and relatively simple manner without weakening the region of the tape adjoining the coupling element and even without the relatively complex means necessary prior thereto for affixing the coupling element to the tape. In this improved system, a fabric-support tape is provided, usually proximal to the edge at which the coupling element is to project but inwardly of the marginal portion of the tape at this edge, with a row of openings spaced apart with an interopening distance corresponding generally to the spacing of the heads of the coupling elements. The continuous (e.g. helicoidally wound) coupling element is inserted with its heads extending through these openings and is anchored to the tape by folding back the marginal portion thereof over the shanks and, possibly, the bight portions of the coupling elements. The tape or band is, advantageously, provided with shrinkable filaments or threads at least extending transversely to this row of openings and interconnecting the marginal portion of the tape with the remainder thereof, whereby the coupling element is mounted upon the tape with the coupling heads passing through the respective openings and the assembly is thereafter treated to shrink at least the threads bordering the openings and to seize the coupling elements to the necks of the respective heads which pass through the latter. Thus the support tape is composed of a shrinkable material, i.e. is woven or knitted from shrinkable threads of the character described, or contains shrinkable filaments together with or incorporated in generally nonshrinkable threads. Alternatively, the shrinkable threads may be interspersed with nonshrinkable threads or disposed only between the openings, while the balance of the threads constituting the fabric are of a nonshrinkable character. Upon shrinkage of the tape, therefore, the threads defining the openings are tightened about and hug the shank portions of the coupling element adjoining the heads while retaining the desired spacing or gauge of the heads of the coupling element. In the system described in this ap- 3,494,008 Patented Feb. 10, 1970 plication, the support tape is composed of a fabric whose threads are shrinkable in the longitudinal (i.e. warp) direction parallel to the row of openings and the coupling elements, as well as transversely of the row of openings (i.e. the weft direction). The stringer shrinkage occurs in the transverse 0r weft direction. Furthermore, the openings may be formed by omitting one or more threads in the weaving operation or by distending or loosening a row of loops when the band is a knitted fabric. The shrinkage can be effected by any conventional means so that, for example, when the shrinkage threads are composed of natural fibers shrinkable in water or chemical solution, the shrinking operation can involve an immersion, spraying or steam-treatment of the tape; it is also desirable and a preferred realization of the process to constitute the shrinkable threads of a thermally contractile fiber, or filament such as nylon which shrinks upon heating to hug and conform to the heads of the slide fastener. The latter are preferably composed of a molecularly oriented thermoplastic monofilamentary synthetic resin, e.g. a nylon-type polyamide, whose coupling heads are formed in the continuous turns of the coupling element by plastic deformation thereof under pressure in a heated condition.

In the modification of this basic system described and claimed in my application Ser. No. 619,768, the tape is woven or knitted with an elongated fabric tube or sleeve along one edge, the tube being provided with a row of lateral openings adapted to receive the spaced-apart heads of a continuous coupling element, e.g. of the helicoidal type described above. The coupling element is here inserted longitudinally into the tube which originally is dimensioned to have a cross-section approximately corresponding to or greater than that of the coupling element, to facilitate longitudinal insertion of the latter. The tube is thereafter subjected to a shrinkage treatment whereby the tube contracts about the coupling element and locks the latter in place on the tape with the heads of the coupling element exposed through the opening. Advantageously, the tube is formed integrally with the remainder of the fabric band, i.e. the web portion thereof, whereby the fabric band may be attached to a support, the openings may be formed by omission of Warp threads in a weaving operation, the slackening of knitted loops, or by weaving the threads in an open-mesh structure. In a modification of this system, the tube may be provided centrally along the tape whose lateral flanges or webs may be folded under to expose the coupling heads along one edge of the respective tape half when the assembly is completed. The fabric tube may be composed of thermoplastic or other shrinkable fiber and can be integrally woven or knitted by conventional techniques used in the production of tubular fabric. When reference is made herein to the weaving or knitting of the tubular sleeve, it is understood that these methods include weaving techniques in which weft and warp threads are interwoven with the warp threads running longitudinally along the band and the weft threads extending transversely so as to constitute of the latter the threads which define the openings through which the heads of the coil are inserted. I have found that it is relatively simple in this arrangement to insert continuous coupling elements of the helicoidal type into the tube which is initially formed with a cross-section equal to or greater than that of the coupling element but which has a shrunk cross-section less than that of the coupling elements. The threads between the heads may be compacted against a core element extending through the coupling member by a toothed coil passing between the heads prior to the shrinkage of the tube. Furthermore, the Warp threads may have only limited shrinkability and can be preshrunk before they are intercollated into the fabric so that a shrinkage of, say, 10% that of the weft threads is sustained by the warp threads in the manner previously described, thereby condensing the cross-section of the tube without materially reducing the length of the band. Some longitudinal shrinkage is, however, desirable when the heads of the coupling elements are to be spaced apart by the weft threads. In this case, the interhead spacing can be accurately established by controlled longitudinal shrinkage of the band to set the desired spread of the heads.

In the modification of the basic principles set forth above and enumerated, described and claimed in application Ser. No. 624,647, the fabric support tape of each slide-fastener half is woven with warp threads running in the longitudinal dimension of the tape and weft threads transversely thereof so as to have a row of throughgoing openings along one edge of the fabric band formed by omission of the corresponding warp threads. At least one relatively thick cord or fillet is anchored to the fabric adjoining the row of openings and a continuous (i.e. a helicoidal coupling element or a meandering coupling element-see U.S. Patents Nos. 3,136,106, 3,243,489 and 3,267,514) is inserted with its heads through the respective openings and is anchored to the tape so that the bead lies along corresponding flanks of the coupling element. Advantageously, the beads lie in planes parallel to the web portions of the respective tapes (by means of which the tapes may be secured to supporting fabric), while the flanks of the coupling elements are generally planar. The resulting bead not only serves as a guide for the slider and as a buffer or securing means for the coupling element, but also partially encloses those portions of the coupling element by which the latter are secured to the tape. In this modification, the helicoidal coupling elements are of deformed cross-section and have generally pear-shaped configuration with relatively enlarged looplike heads matingly interengageable with the corresponding heads of another coupling element, but with shanks which lie in planes perpendicular to the webs so that the heads can be relatively close-spaced. Here again, shrinkage is effected to clamp the coupling elements in place.

In these systems and in earlier arrangements in which the coupling elements have been inserted through openings in the fabric band, problems have been encountered as a result of withdrawal of coupling elements therethrough. Thus, in some of the systems described above and in certain prior-art arrangements in which the coupling element is partially enveloped in the fabric band which has previously been formed with a row of openings adapted to receive the heads of the coupling element, it has been necessary to stitch (eg by a line of chainstitching) or otherwise to secure the shanks of the coupling elements to the support web to prevent such withdrawal of the coupling heads which was capable of rendering the slide fastener useless.

It is, therefore, the principal object of the present invention to provide an improved method of making slidefastener assemblies and an improved stringer whereby the aforementioned disadvantages are avoided and the coupling element can be anchored upon its support tape without danger that the heads will withdraw through the openings provided in the band.

A further object of this invention is to extend the principles originally set forth in the above-identified applications and to provide a slide fastener whose useful life is increased.

I have now found that systems in which the coupling element is locked in place by shrinkage 'of the fabric band about the coupling element (see the above-identified copending applications) as well as earlier arrangements in which the helicoidal coupling elements were inserted through openings in a fabric band are incapable of ensuring permanent emplacement of the heads within the openings provided in the fabric band unless augmented by a stitchin process or by precluding movement of the C pling element with a, sleeve or tube formation of the tape. These specified procedures can be avoided, according to the present invention, by providing a generally helicoidal coupling element of a thermoplastic monofilamentary synthetic resin Whose turns are formed (e.g. by thermoplastic deformation) with coupling heads interengageable with the corresponding coupling heads of a mating coupling element, the heads being inserted through the spaced-apart openings of a support tape; transversely of these coupling heads and along the side of the coil having the coupling heads, I provide arresting means for retaining the heads in the respective openings. The openings, which may be formed as described earlier by omitting warp or weft threads in a weaving operation or by dropping a knitted loop, course or Wale, thus are bridged by an arresting thread outwardly of the channel or sleeve provided by the tape while chain-stitching or other anchor means can be eliminated.

According to a more specific and important feature of this invention, the arresting or retaining means is formed on the coupling elements proximal to their respective rows of heads and alon one or both flanks of the cou pling element. The retaining member may, therefore, be a thermoplastic synthetic resin monofilament which is thermally bonded to the coupling heads, the retaining thread thus extending longitudinally along the coupling element for a major part of the length of the slide fastener. The retaining member is preferably flexible and extensible in the longitudinal sense to permit coupling and decoupling of the slide-fastener halves and is readily workable to admit of easily mounting upon the coupling elements.

The retaining filament can, moreover, be formed on the coupling elements in various ways, e.g. prior to the deformation of the coupling heads, thereafter or concurrently with this deformation. It is also possible to provide the coupling elements as additional members or to form the coupling element exclusively by deformation of the coupling heads or the shanks adjoining same. Thus the elongated retaining member may be formed wholly from the material constituting the coupling elements or may be a separate member applied thereto.

According to a more specific feature of this invention, a particularly firm retention of the coupling element is ensured by providing the retaining member as a thread, bead or filament along the coupling element for its full length and united with the coupling element, preferably by thermal bonding and deformation such that it is formfitted to the coupling element. The aforementioned copending applications and the cited U.S. patents, together with those of the same class, describe various methods of deforming the coupling elements, these methods being equally suitable to the step of integrating and formfitting the retaining thermoplastic thread to the thermoplastic coupling elements and may involve pressure rollers, toothed wheels, dies and the like used to deform the coupling-element strands. The retaining element may lie along one or both flanks of the coupling heads or may be bonded to the couplin element while belng disposed within the loops formed by the heads against the fabric portions extending therewithin and bordering the openings. Furthermore, a fillet, filler cord or core of an elastomeric or flexible material (e.g. as described in the copending applications mentioned above) is received within the coupling coil and has the fabric in the region of the openings folded therearound. The fabric band is thus sandwiched between the retaining formations or filament and this cord.

The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a plan view of one-half of a slide-fastener stringer, according to the present invention;

FIG. 2 is a cross-sectional view taken a ong the line IIII of FIG. 1;

FIG. 3 is a side view taken in the direction of arrow III of FIG. 1;

FIG. 4 is a view similar to FIG. 1 of a modified slidefastener half;

FIG. 5 is a cross-sectional view along the line V-V of FIG. 4;

FIG. 6 is a side view taken in the direction of arrow VI of FIG. 4;

FIG. 7 is a plan view of a slide fastener of the type illustrated in FIGS. 1-3, showing the coupling elements in their mutually interleaved and engaged positions;

FIG. 8 is a cross-sectional view taken along the line VIII-VIII of FIG. 7;

FIG. 9 is a view similar to FG. 1 of still another modification; and

FG. 10 is a cross-sectional view along the line XX of FIG. 9.

In FIGS. 1-3 of the drawing, I show half of a slidefastener stringer which comprises a flattened helicoidal coil 1 constituting a coupling element 2 and having spaced-apart coupling heads 3 whose protuberances 3a and 312 project laterally from the flattened heads, which can be formed by thermoplastic deformation of the synthetic resin monofilamentary strand forming the coil 1 (e.g. of nylon-type polyamide) by any of the devices described and illustrated in the aforementioned copending applications and letters patent. The heads 3 lie in respective planes P perpendicular to the axis X of the helicoidal coil 1 and have at each turn a pair of shanks 3c and 3d which lie in the plane P. The shanks of successive turns are interconnected by respective bight portions 32 as illustrated in FIGS. 1 and 2. The coupling heads 3 are inserted through the openings 4 which are produced ;by omitting warp threads in the woven fabric strip 6 which may have a web 6a stitched onto a support band 10 as well as a marginal portion 5 covering the shanks 3c and 3d as described and claimed in the aforementioned copending applications. The marginal portion 6 is thus turned about a core element or filler cord 8 which extends through the coil and serves as a stop for the weft threads 11 bridging the marginal portion 5 and the web 6a of the fabric strip 6. The retaining means 7, 7', according to the present invention, is here constituted as a pair of thermoplastic strands formed on the turns of the coupling element adjacent the heads 3 which sandwich the weft threads 11 between the filler cord '8 and themselves. The strand 7 or 7 is an additional element (e.g. a nylon thread) thermally bonded to the coil 1 on the opposite flanks (i.e. above and below) of the coupling element 2. Corresponding retaining members extending in the direction of the coupling element ahead of the web are illustrated in FIGS. 9 and 10. Here the fabric band 16 has a marginal portion turned about the filler cord 18 While the retaining means 17 is constituted as a pair of lateral formations 17' and 17" molded unitarily from the thermoplastic of the coil 12 and retaining the heads 13 against withdrawal through the openings of the band. The coupling elements 17' and 17" are provided on each flank so that they form a substantially continuous retaining formation along the entire length of slide fastener.

In the modification of FIGS. 4 6, the coupling heads 23 of coupling element 22 emerge through openings 24 between the weft threads and the retaining strand 27 is disposed within the loops formed by the heads 23 against these weft threads along the entire length of the slide fastener strip. The marginal portion 25 of fabric is turned about the flanks of coil 21 which overlies the fabric strip 26. Although thermal bonding of the member 7, 7' and 27 to the coupling element between the web and the heads 23 is preferred, it will be understood that other methods of mounting the retaining strands can be used. Thus the retaining strands can be defromed so as to interengage the shanks of the strands and to be nonshiftable relatively thereto via the use of mating formations on the retaining strands and the inner or outer flanks of the shanks depending upon whether the retaining element is disposed as at 27 within the coil or, as at 7 and 7', externally thereof. Adhesive methods (e.g. via solvent fusion) may also be employed.

As will be apparent from FIGS. 7 and 8, the retaining strands 7 simultaneously engage the heads 3 of the coupling elements when they are mutually interfitted (FIG. 8) and prevent transverse shifting as represented by arrows B and C. To this end, the distance d between the elements 7 and 7 of each coupling element should be approximately equal to the width of the head 3 engaged thereby. The resulting slide fastener is difficult to separate and has a higher coupling strength than systems proposed earlier. Furthermore, this strength is augmented by the use of filler cords whereby the weft threads between the openings are sandwiched between the continuous filler cord and the continuous retaining formations.

It will be understood that the invention, while described in connection with helicoidal coupling elements, is applicable as well to meandering coupling elements; all such modifications and variations, readily recognized by those skilled in the art, are intended to be included within the spirit and scope of the invention.

1. A slide-fastener assembly comprising a pair of slidefastener halves each having a respective support band provided with spaced-apart openings, a respective continuous coupling element having spaced-apart heads respectively extending through said openings, and at least one retaining formation formed on said coupling element transversely of said heads along said openings for preventing withdrawal of said heads through said openings, said retaining formation being at least one strand formed along said coupling element and secured thereto, said coupling element being a helicoidal coil having said heads formed upon successive turns of said coil, each of said turns including a pair of shanks extending through the respective opening and forming a loop with the respective head, said strand being received within said loops and is bonded to said shanks ahead of said band.

2. A slide-fastener assembly comprising a'pair of slidefastener halves each having a respective support band provided with spaced-apart openings, a respective continuous coupling element having spaced-apart heads respectively extending through said openings, and at least one retaining formation formed on said coupling element transversely of said heads along said openings for preventing withdrawal of said heads through said openings, said retaining formation being at least one strand formed along said coupling element and secured thereto, said coupling element being a helicoidal coil having said heads formed upon successive turns of said coil, each of said turns including a pair of shanks extending through the respective opening and forming a loop with the respective head, said strand being molded around and formfitting about the turns of said coil.

3. The assembly defined in claim 2 wherein a pair of said strands is provided along opposite outer flanks of said shanks of said coil and are bonded thereto.

4. The assembly defined in claim 3 wherein the strands of the respective coil have a transverse spacing approximately equal to the width of the heads of the other coupling element for restricting transverse relative movement of the coupling elements upon their interengagement.

5. The assembly defined in claim 1 wherein said strand and said coil are composed of thermoplastic material and are thermally fused together.

6. The assembly defined in claim 1, further comprising a filler cord extending through each of said coils inwardly of the respective openings.

7. The assembly defined in claim 1, wherein said retaining formation extends the full length of the slide 7 8 fastener and is at least in part molded from the turns of 3,136,016 6/ 1964 Firing 24205.1 the respective coil. 3,179,996 4/1965 Clauss 24-205.]

3,247,871 4/1966 Lacam. References Cited UNITED STATES PATENTS 5 BERNARD A. GELAK, Primary Examiner 2,296,880 9/1942 Smith. 1 3,022,803 2/1962 Berberich. 24205.16 

